DOMINO - Drivers Of Mid-pleIstoceNe glaciatiOn? Novel multiproxy approach to track oceanic-atmospheric-cryospheric controls on climate responses (FWOTM1094)

The ongoing climate changes prediction requires to discriminate the
natural drivers (orbital, cryosphere, atmospheric…) of the Earth’s
system from human activities. To do so, the climate variability of
orbital analogues to the Holocene must be examined in detail. The
Mid-Pleistocene Transition (MPT, 1 Ma ago) is a key climate period in
this context: it marks the transition towards the current climate and
one interglacial had similar orbital configurations as today. However,
the natural drivers of the MPT are still debated. DOMINO proposes to
deliver key climate data to identify these drivers. A novel approach is
developed by combining the powerful clumped-isotope thermometer
with Mg/Ca method in microfossils to reconstruct changes in
temperatures, ice sheet volume and atmospheric [CO2]. DOMINO
also tracks the changes in weathering by testing the unique
combination of Sr and Os isotopes in Quaternary sediment. This
methodological approach is highly promising to accurately
reconstruct the key climatic parameters across the MPT. First, a
selected sediment core in the North Atlantic Ocean is used to
examine oceanic, atmospheric and cryospheric interactions. Then, a
second core in the Bay of Bengal documents the potential role of the
Indian monsoon. The results provide the needed framework to
precisely define the driver’s actions (ice sheet vs monsoon).
DOMINO pioneers through application of a unique multiproxy
approach and improves understanding of the Earth’s climatic system..

Keywords:Clumped-isotope carbonate, Mid-Pleistocene transition, Foraminiferal trace elements

Disciplines:Geochemistry not elsewhere classified, Quaternary environments, Palaeoclimatology, Marine geoscience, Climate change